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(No Model.) 4 Sheets-Sheet 1.

0. HOFFMANN & E. RICHTER. UTILIZING ELECTRIC MOTORS FOR OPERATINGMACHINERY.

4 No. 496,567. Patented May 2, 1893.

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(No Model.) 4 Sheets-Sheet 2,

. 0. HOEFMANN & E. RICHTER. UTILIZING ELECTRIC MOTORS FOR OPERATINGMACHINERY.

N0. 496,567. v Patented May 2, 1893.

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I 0. HOFFMANN 82; B. RICHTER. UTILIZING ELBOTBIO MOTORS FOR OPERATINGMAOHINERY.

No. 496,567. 7 Patented MayZ, 1893.

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(No Model.) 4 Sheets-'-Sheet 4.

G. HOPFMANN 8; E. RICHTER. 4 UTILIZING ELECTRIC MOTORS FOR OPERATINGMACHINERY} No. 496,567. Patented May 2, 1893.

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Unwrap STATES PATENT OFFICE.

CARL HOFFMANN AND ERNST RICHTER, OF BERLIN, GERMANY, ASSIGNORS TOSIEMENS & HALSKE, OF SAME PLACE.

UTILIZING ELECTRIC MOTORS FOR OPERATING MACHINERY.

SPECIFICATION forming part of Letters Patent No. 496,567, dated May 2,1893.

Application filed November '7, 1892. Serial No. 451,242. (No modelPatented in Germany February 9, 1893, No. 66,984.

T0 at whom it may concern:

Be it known that we, CARL HOFFMANN and ERNST RICHTER, subjects of theKing of Prussia, German Emperor, residing in the city of Berlin, Kingdomof Prussia, German Empire, have invented new and usefulImprovements inUtilizing Electric Motors for Operating Machinery, of which thefollowing is a specification.

The object of ourinvention is to practically and advantageously utilizeelectric motors for operating other machines or apparatus in a mannerwhich will most effectively and economically transmit the power of themotor to the machine driven by it, for which we have obtained LettersPatent in Germany, No 66,984, dated February 9, 1893.

It is well known that in order to get the best operative results from anelectric motor, it is essential that it be run at a practically uniformspeed.

In carrying out our invention, we sustain the electric motor in movablerelation to the machine driven by it and avail ourselves of the weightor gravity of the motor in transmiting power to the machine by means offlexible appliances which may be modified by bodily movement of themotor, and whereby any desired speed may be given the driven machine orapparatus, without appreciably or injuriously slackening or varying thespeed of the electric motor.

Our improvements also involve other novel features and detailshereinafter more fully described.

In the accompanying drawings forming part of this specification, Figure1 is a side View of a power machine, having a driving motor combinedtherewith, in accordance with our improvements. Fig. 2 is a front view;Fig. 3, a plan view of the apparatus illustrated in Fig. 1. Fig. 4 is aside elevation of a power machine combined with a motor, in accordancewith our improvements and showing a modification. Fig. 5 is a. frontelevation of the apparatus shown in Fig. 4:; and Fig. 6 is a diagramillustrating the movable relation of the motor and transmitting gearingwith respect to the power machine.

A platform A is pivotally supported at one end by a shaft B, secured inthe lower portion of the frame of the power machine, or otherwisesuitably supported so that its outer end may be freely movable in anupward or downward direction. Upon this platform is mounted a smallelectric motor C for driving the power machine. A bracket or frame D ispivotally connected at d to the power ma chine adjacent to its bed, andcarries in its upper free portion a shaft (1, upon which is mounted aband wheel 9 and a graduated or cone pulley b. The power of the motor Cis transmitted through the pulley 6 upon its armature shaft by the beltf to the band wheel g, andt'nence through the beltdto the graduated orcone pulley o, mounted on the shaft 0' of the power machine. On theshaft 0 are also the gears c and c, which respectively mesh with thecorresponding gears c and 0 mounted on the shaft 0 A lever E is pivotedon one of the lower cross-bars of the machine frame and is provided atone end with a treadle plate, while its forward end is. attached to theframe D by means of a rgd 1'.

With the parts constructed and arranged as described, the frictionalrelation of the transmitting gearing will be normally positivelymaintained, since in the first instance, the tension of the belt at ispreserved by the weight of the frame D, and the parts carried therebyplus the suspended weight of the motor, exerted through the belt f. Itwill be readily understood that such conditions serve to efiect thecommunication of the full speed of the motor to the power machine.

Now, should it be desired to modify or interrupt the speed of the powermachine, to permit the belt at to be shifted, or for any other object,the treadle end of the lever is depressed by the foot of the attendant,so that the frame D and, suspended motor are elevated to relieve thetension of belt (1, thereby modifying the transmitted speed inproportion to the degree of elevation of the frame D. It will thereforebe understood that such an operation is highly advantageous since, asbefore generally explained, the desired modification of the speed of thepower machine can be effected without in any way varying or affectingthe speed of the motor.

The normal tension of the belt 61 is best illustrated by the diagram,Fig. 6, wherein p line 1 refers to the belt, line 2, the frame D, andlines 3 and 4, the compound tension force exerted by the suspended motoron the belt d.

In Figs. 4 and 5, we have shown a construction modified to adapt theimprovements for use in connection with arrangements wherein the powermachine is driven by means of frietional contact pulleys. The frame D ispivoted at its inner end and carries the graduated friction pulleys b infrictional relation with a set of corresponding pulleysj, turning with acounter shaft k the end gear pinion Z of which permanently engages thedriven gear wheel m of the power machine.

The frictional engagement of the pulleys b and j is normally maintainedby the weight of the motor acting through the belt f on the band wheel gon the end of shaft a, to which motion is communicated by said belt. Therelatively reversed graduated pulleys bj are of equal dimensions, sothat they would, in the absence of special provision to the contrary,bear a fixed relation to each other. In order, however, to permit thefrictional engagement of any one of the driving pulleys b, with theopposite driven pulley j, and maintain the other pulleys out ofoperative contact, we cmploy a belt or band F, which passes over one ofthe pulleysj and is given the desired tension by means of a weight 97.,carrying a pulley 0 hung on said belt.

The thickness of belt interposed between any one of the pulleys b andopposite pulley j will be sufficient to insure the communication ofmovement from the former to the latter while the other pulleys are outof engagement. By slightly elevating the frame D, the belt F can bereadily shifted from one pulley j to another and thereby vary the degreeof transmitted speed without modifying the action of the motor.

The weight a suspended by the pulley 0 enables the belt F to have atravel corresponding with the frictional motion transmitted, so that thebelt will not bind nor offer any objeetionable resistance to thefrictional transmission. This last described modified construction shownin Figs. 4 and 5, is not essentially different in some features from theother construction shown in Figs. 1, 2, and 3 of the drawings, as inboth constructions the machine to be operated has a pivoted framecarrying gearing which transmits to the operative shaft or part of themachine the power derived through the belt f from the electric motor.The construction shown in Figs. 4 and 5, however, provide fortransmission of the power by utilizing the weight of the electric motorthrough the belt f, the pivoted frame D, and the cone pulley 19 upon thecounterweighted belt F, in frictional contact with one of the pulleys ofthe lower cone pulley j which is geared at Z, 171, to the operative partor shaft of the machine to be driven, and change of speed of the machineis provided for by simply shifting the counterweighted belt F, laterallybetween the opposing cone pulleys 12, of the machine, instead of beingeffected by means of the treadle and rodconnections E, i, as in thefirst described construction shown in Figs. 1, 2 and 3 of the drawings.We intend, however, to make a separate application to patent thisspecial feature of using the counterweighted belt F between the conepulleys of a machine operated by an electric motor. e also speciallymention the fact that in the construction shown in Figs. 1 and 2 of thedrawings, the driving beltf remains taut between the motor pulleyeandthe machine pulley 9, during the lifting of the pivoted frame D, by thetreadle connections E, 't' and the consequent yielding or slackening ofthe belt cl, which slips more or less on the cone pulleys to vary thespeed of the operative spindle or part of the machine, and to an extentdepending upon the range of depression of the treadle lever by theattendant.

e claim- 1. The combination with apower machine, of an electric motorand frictional transmission gear, the motor being movable in itsrelation to the power machine to modify the transmission gear andthereby vary the speed of the power machine without varying the speed ofthe electric motor.

2. The combination with a power machine, of a suspended electric motorand frictional transmission gear held in operative relation by theweight of the motor, the movable eapability of the latter serving topermit the variation of the transmission gear and thereby the speed ofthe power machine without varying the speed of the electric motor.

The combination with a power machine, of a movable frame carryingtransmission gearing for driving the power machine, and a pivotallysupported electric motorsuspended by its driving belt from the framegearing, substantially as described.

4. The combination with a power machine, of a movable frame carryingtransmission gearing for the power machine, a movable electric motorsuspended by its driving belt from the frame gearing, and a foot leverand connection for vertically moving the frame to modify the relation ofthe transmission gearing, substantially as described.

5. The combination with a power machine, of a movable frame carryingtransmission gearing imparting motion to the power machine by a belt,and an electric motor geared with the transmission gearing by a belt,said motor being movable in its relation to the power machine to releaseor slack the belt between the latter and the transmission gearing andstill maintain the motor belt taut, substantially as described.

6. The combination with a power machine, of an electric motor,interposed mechanism for transmitting the power of the motor to thepower machine, and means, substantially as described, for varying theenergy transmitted without varying the speed of the motor.

ITO

7. The combination with a power machine,

of an electric motor, interposed mechanism for transmitting the power ofthe motor to the power machine, and means for varying the energytransmitted without varying the speed of the motor, whichmeans consistsof mechanism which acts to modify the effective weight of the motor andthereby effect alterations in the speed of the power machine.

8. The combination with a power machine, of an electric motor,interposed flexible mechanism for transmitting the power of the motor tothe power machine, and means for Varying the power transmitted withoutvarying the speed of the motor, by varying the tension exerted by theweight of the motor upon the flexible transmitting mechanism.

9. The combination with a power machine,

of a pivoted platform, an electric motor mounted upon said platform, apivoted frame carrying a band wheel and a graduated or cone pulley, abelt interposed between the band wheel and the electric motor, a beltinterposed between the graduated or cone pulley on the pivoted frameanda similar pulley upon the power machine, and a device for varying thetension of said last named belt, to vary. the speed of the powermachine.

In testimony whereof we have aflixed our signatures in the presence oftwo witnesses.

CARL HOFFMANN. ERNST RICHTER.

Witnesses GUSTAV STENZEL, MAX WAGNER.

